diff options
Diffstat (limited to 'Lib')
| -rw-r--r-- | Lib/shutil.py | 43 | ||||
| -rw-r--r-- | Lib/test/test_os.py | 38 | ||||
| -rw-r--r-- | Lib/test/test_shutil.py | 48 |
3 files changed, 128 insertions, 1 deletions
diff --git a/Lib/shutil.py b/Lib/shutil.py index db80faf..6664599 100644 --- a/Lib/shutil.py +++ b/Lib/shutil.py @@ -878,3 +878,46 @@ def chown(path, user=None, group=None): raise LookupError("no such group: {!r}".format(group)) os.chown(path, _user, _group) + +def get_terminal_size(fallback=(80, 24)): + """Get the size of the terminal window. + + For each of the two dimensions, the environment variable, COLUMNS + and LINES respectively, is checked. If the variable is defined and + the value is a positive integer, it is used. + + When COLUMNS or LINES is not defined, which is the common case, + the terminal connected to sys.__stdout__ is queried + by invoking os.get_terminal_size. + + If the terminal size cannot be successfully queried, either because + the system doesn't support querying, or because we are not + connected to a terminal, the value given in fallback parameter + is used. Fallback defaults to (80, 24) which is the default + size used by many terminal emulators. + + The value returned is a named tuple of type os.terminal_size. + """ + # columns, lines are the working values + try: + columns = int(os.environ['COLUMNS']) + except (KeyError, ValueError): + columns = 0 + + try: + lines = int(os.environ['LINES']) + except (KeyError, ValueError): + lines = 0 + + # only query if necessary + if columns <= 0 or lines <= 0: + try: + size = os.get_terminal_size(sys.__stdout__.fileno()) + except (NameError, OSError): + size = os.terminal_size(fallback) + if columns <= 0: + columns = size.columns + if lines <= 0: + lines = size.lines + + return os.terminal_size((columns, lines)) diff --git a/Lib/test/test_os.py b/Lib/test/test_os.py index 4d27c2b..8dd745a 100644 --- a/Lib/test/test_os.py +++ b/Lib/test/test_os.py @@ -1840,6 +1840,43 @@ class Win32DeprecatedBytesAPI(unittest.TestCase): os.symlink, filename, filename) +@unittest.skipUnless(hasattr(os, 'get_terminal_size'), "requires os.get_terminal_size") +class TermsizeTests(unittest.TestCase): + def test_does_not_crash(self): + """Check if get_terminal_size() returns a meaningful value. + + There's no easy portable way to actually check the size of the + terminal, so let's check if it returns something sensible instead. + """ + try: + size = os.get_terminal_size() + except OSError as e: + if e.errno == errno.EINVAL or sys.platform == "win32": + # Under win32 a generic OSError can be thrown if the + # handle cannot be retrieved + self.skipTest("failed to query terminal size") + raise + + self.assertGreater(size.columns, 0) + self.assertGreater(size.lines, 0) + + def test_stty_match(self): + """Check if stty returns the same results + + stty actually tests stdin, so get_terminal_size is invoked on + stdin explicitly. If stty succeeded, then get_terminal_size() + should work too. + """ + try: + size = subprocess.check_output(['stty', 'size']).decode().split() + except (FileNotFoundError, subprocess.CalledProcessError): + self.skipTest("stty invocation failed") + expected = (int(size[1]), int(size[0])) # reversed order + + actual = os.get_terminal_size(sys.__stdin__.fileno()) + self.assertEqual(expected, actual) + + @support.reap_threads def test_main(): support.run_unittest( @@ -1866,6 +1903,7 @@ def test_main(): ProgramPriorityTests, ExtendedAttributeTests, Win32DeprecatedBytesAPI, + TermsizeTests, ) if __name__ == "__main__": diff --git a/Lib/test/test_shutil.py b/Lib/test/test_shutil.py index c72bac2..4d0ef29 100644 --- a/Lib/test/test_shutil.py +++ b/Lib/test/test_shutil.py @@ -9,6 +9,7 @@ import os import os.path import errno import functools +import subprocess from test import support from test.support import TESTFN from os.path import splitdrive @@ -1267,10 +1268,55 @@ class TestCopyFile(unittest.TestCase): finally: os.rmdir(dst_dir) +class TermsizeTests(unittest.TestCase): + def test_does_not_crash(self): + """Check if get_terminal_size() returns a meaningful value. + + There's no easy portable way to actually check the size of the + terminal, so let's check if it returns something sensible instead. + """ + size = shutil.get_terminal_size() + self.assertGreater(size.columns, 0) + self.assertGreater(size.lines, 0) + + def test_os_environ_first(self): + "Check if environment variables have precedence" + + with support.EnvironmentVarGuard() as env: + env['COLUMNS'] = '777' + size = shutil.get_terminal_size() + self.assertEqual(size.columns, 777) + + with support.EnvironmentVarGuard() as env: + env['LINES'] = '888' + size = shutil.get_terminal_size() + self.assertEqual(size.lines, 888) + + @unittest.skipUnless(os.isatty(sys.__stdout__.fileno()), "not on tty") + def test_stty_match(self): + """Check if stty returns the same results ignoring env + + This test will fail if stdin and stdout are connected to + different terminals with different sizes. Nevertheless, such + situations should be pretty rare. + """ + try: + size = subprocess.check_output(['stty', 'size']).decode().split() + except (FileNotFoundError, subprocess.CalledProcessError): + self.skipTest("stty invocation failed") + expected = (int(size[1]), int(size[0])) # reversed order + + with support.EnvironmentVarGuard() as env: + del env['LINES'] + del env['COLUMNS'] + actual = shutil.get_terminal_size() + + self.assertEqual(expected, actual) def test_main(): - support.run_unittest(TestShutil, TestMove, TestCopyFile) + support.run_unittest(TestShutil, TestMove, TestCopyFile, + TermsizeTests) if __name__ == '__main__': test_main() |